Manufacture method of TFT substrate and sturcture thereof

ABSTRACT

The present invention provides a manufacture method of an oxide semiconductor TFT substrate, and the method comprises steps of:  1,  forming a gate ( 2 ) on a substrate ( 1 );  2,  deposing a gate isolation layer ( 3 );  3,  forming an island shaped oxide semiconductor layer ( 4 );  4,  forming an island shaped photoresistor layer ( 6 ) and an island shaped etching stopper layer ( 5 ), and the island shaped etching stopper layer ( 5 ) covers a central part ( 41 ) of the island shaped oxide semiconductor layer ( 4 ) and exposes two side parts ( 43 ) of the island shaped oxide semiconductor layer ( 4 );  5,  implementing ion implantation process to the two side parts ( 43 ) of the island shaped oxide semiconductor layer ( 4 );  6,  lifting off the island shaped photoresistor layer ( 6 );  7,  forming a source/a drain ( 7 ), and the source/the drain ( 7 ) contact the two side parts ( 43 ) of the island shaped oxide semiconductor layer ( 4 ) to establish electrical connections;  8,  deposing and patterning a protecting layer ( 8 );  9,  deposing and patterning a pixel electrode layer ( 9 );  10 , implementing anneal process.

FIELD OF THE INVENTION

The present invention relates to a display technology field, and moreparticularly to a manufacture method of an oxide semiconductor TFTsubstrate and a structure thereof.

BACKGROUND OF THE INVENTION

A flat panel display possesses advantages of being ultra thin, powersaved and radiation free and has been widely utilized. Present flatpanel displays mainly comprise a LCD (Liquid Crystal Display) or an OLED(Organic Light Emitting Display).

To be compared with a well developed TFT-LCD, an OLED based on theOrganic Light Emitting Diodes is an active light emitting display, whichpossesses outstanding properties of self-illumination, high contrast,wide view angle (up to 170°), fast response, high luminous efficiency,low operation voltage (3-10V), ultra-thin (thickness smaller than 2 mm)and etc. The display devices utilizing OLED technology has possibilityto have a lighter, thinner, charming appearance, more excellent colordisplay quality, wider view range and greater design flexibility.

Thin Film transistors (TFT) are important components of a flat paneldisplay which can be formed on a glass substrate or a plastic substrate.Generally, the tin film transistors are employed as light switching-onelements and driving elements utilized such as LCDs, OLEDs,Electrophoresis Displays (EPD).

The oxide semiconductor TFT technology is the most popular skill atpresent. Because the carrier mobility of the oxide semiconductor is20-30 times of the amorphous silicon semiconductor. With the higherelectron mobility, it is capable of magnificently raising thecharging/discharging rate of TFT to the pixel electrodes to promote theresponse speed of the pixels and to realize faster refreshing rate. Inthe mean time, the line scan rate of the pixels also can be promoted tomake the manufacture of the flat panel display having ultra highresolution become possible. In comparison with the Low TemperaturePoly-silicon (LTPS), the oxide semiconductor manufacture process issimpler and possesses higher compatibility with the amorphous siliconprocess. It can be applicable to the skill fields of Liquid CrystalDisplay, Organic Light Emitting Display, Flexible Display and etc.Because it fits the new generation production lines and has possibleapplications for displays with Large, Middle and Small sizes. The oxidesemiconductor has the great opportunity of application development.

In a present oxide semiconductor TFT substrate structure, the oxidesemiconductor layer generally contacts the source/the drain directlywithout treatment in general and form electrical connectionstherebetween. However, the ohm contact resistance inbetween is largerand leads to higher driving voltage and higher power consumption of theflat panel display.

The power saving is real a required topic to the development of thepresent society. Making great efforts to develop low power consumptionflat panel display becomes an important target to all flat panel displaymanufacturers.

SUMMARY OF THE INVENTION

An objective of the present invention is to provide a manufacture methodof an oxide semiconductor TFT substrate capable of improving the ohmcontact between the oxide semiconductor layer and the source/the drainto reduce the ohm contact resistance therebetween. The driving voltageof the flat panel display can be reduced and accordingly the powerconsumption of the flat panel display can be effectively diminished.

Another objective of the present invention is to provide an oxidesemiconductor TFT substrate structure, which the ohm contact resistancebetween the oxide semiconductor layer and the source/the drain issmaller to reduce the driving voltage of the flat panel display and todiminish the power consumption of the flat panel display.

For realizing the aforesaid objective, the present invention provides amanufacture method of an oxide semiconductor TFT substrate, comprisingsteps of:

step 1, providing a substrate, and deposing and patterning a first metallayer on the substrate to form a gate;

step 2, deposing a gate isolation layer on the gate and the substrate;step 3, deposing and patterning an oxide semiconductor layer on the gateisolation layer to form an island shaped oxide semiconductor layerdirectly over the gate;

step 4, sequentially deposing an etching stopper layer, a photoresistorlayer on the island shaped oxide semiconductor layer and the gateisolation layer, and then implementing photolithography process to thephotoresistor layer to form an island shaped photoresistor layerdirectly over the island shaped oxide semiconductor layer, and etchingthe etching stopper layer to form an island shaped etching stopper layeron the island shaped oxide semiconductor layer;

a width of the island shaped etching stopper layer is smaller than awidth of the oxide semiconductor layer; the island shaped etchingstopper layer covers a central part of the island shaped oxidesemiconductor layer and exposes two side parts of the island shapedoxide semiconductor layer;

step 5, implementing ion implantation process to the two side parts ofthe island shaped oxide semiconductor layer;

step 6, lifting off the island shaped photoresistor layer from theisland shaped etching stopper layer;

step 7, deposing and patterning a second metal layer on the islandshaped etching stopper layer and the gate isolation layer to form asource/a drain;

the source/the drain contact the two side parts of the island shapedoxide semiconductor layer to establish electrical connections;

step 8, deposing and patterning a protecting layer on the source/thedrain and the etching stopper layer to form a via located at one side ofthe island shaped oxide semiconductor layer;

step 9, deposing and patterning a pixel electrode layer on theprotecting layer;

the pixel electrode layer fills the via and contacts the source/thedrain to establish electrical connections;

step 10, implementing anneal process to the substrate obtained in theninth step.

Operations of the patterning are accomplished by photolithographyprocess and etching process.

The island shaped oxide semiconductor layer is an IGZO semiconductorlayer.

The ion implantation process is implemented with hydrogen plasma.

Material of the pixel electrode layer is ITO or IZO.

Material of the protecting layer is SiO₂ or SiON.

The substrate is a glass substrate.

The present invention further provides an oxide semiconductor TFTsubstrate structure, comprising a substrate, a gate on the substrate, agate isolation layer on the gate and the substrate, an island shapedoxide semiconductor layer directly over the gate on the gate isolationlayer, an island shaped etching stopper layer on the island shaped oxidesemiconductor layer, a source/a drain on the island shaped etchingstopper layer and the gate isolation layer, a protecting layer on thesource/the drain and the etching stopper layer and a pixel electrodelayer on the protecting layer; the island shaped oxide semiconductorlayer comprises a central part and two side parts, and the two sideparts are implemented with ion implantation process, a width of theisland shaped etching stopper layer is smaller than a width of the oxidesemiconductor layer and only a central part is covered; the source/thedrain contact the two side parts to establish electrical connections;the protecting layer comprises a via located at one side of the islandshaped oxide semiconductor layer, and the pixel electrode layer fillsthe via and contacts the source/the drain to establish electricalconnections.

The island shaped oxide semiconductor layer is an IGZO semiconductorlayer, and material of the pixel electrode layer is ITO or IZO andmaterial of the protecting layer is SiO₂ or SiON.

The substrate is a glass substrate.

The benefits of the present invention are: according to the manufacturemethod of the oxide semiconductor TFT structure of the presentinvention, by implementing ion implantation process to the two sideparts of the island shaped oxide semiconductor layer, the conductingability of the two side parts are raised and the two side parts contactthe source/the drain, which are capable of promoting the ohm contactbetween the oxide semiconductor layer and the source/the drain to reducethe ohm contact resistance therebetween. The driving voltage of the flatpanel display can be reduced and accordingly the power consumption ofthe flat panel display can be effectively diminished; according to theoxide semiconductor TFT structure of the present invention, byimplementing ion implantation process to the two side parts of theisland shaped oxide semiconductor layer and contacts with the source/thedrain, the ohm contact resistance between the oxide semiconductor layerand the source/the drain is smaller to reduce the driving voltage of theflat panel display and to diminish the power consumption of the flatpanel display.

BRIEF DESCRIPTION OF THE DRAWINGS

The technical solution, as well as beneficial advantages, of the presentinvention will be apparent from the following detailed description of anembodiment of the present invention, with reference to the attacheddrawings.

In drawings,

FIG. 1 is a flowchart of a manufacture method of an oxide semiconductorTFT substrate according to the present invention;

FIG. 2 is a diagram of step 1 in the manufacture method of the oxidesemiconductor TFT substrate according to the present invention;

FIG. 3 is a diagram of step 2 in the manufacture method of the oxidesemiconductor TFT substrate according to the present invention;

FIG. 4 is a diagram of step 3 in the manufacture method of the oxidesemiconductor TFT substrate according to the present invention;

FIG. 5 is a diagram of step 4 in the manufacture method of the oxidesemiconductor TFT substrate according to the present invention;

FIG. 6 is a diagram of step 6 in the manufacture method of the oxidesemiconductor TFT substrate according to the present invention;

FIG. 7 is a diagram of step 7 in the manufacture method of the oxidesemiconductor TFT substrate according to the present invention;

FIG. 8 is a diagram of step 8 in the manufacture method of the oxidesemiconductor TFT substrate according to the present invention;

FIG. 9 is a diagram of step 9 in the manufacture method of the oxidesemiconductor TFT substrate according to the present invention and adiagram of the oxide semiconductor TFT substrate structure according tothe present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In order to better understand the characteristics and technical aspectof the invention, please refer to the following detailed description ofthe present invention is concerned with the diagrams.

Please refer to FIG. 1, which is a flowchart of a manufacture method ofan oxide semiconductor TFT substrate according to the present invention,comprising steps of:

step 1, please refer to FIG. 2, providing a substrate 1, and deposingand patterning a first metal layer 2 on the substrate 1.

The substrate 1 is a transparent substrate. Preferably, the substrate 1is a glass substrate.

In the step 1, the photolithography process is implemented with onegeneral mask, and then the etching process is implemented to pattern thefirst metal layer to form a gate 2.

step 2, please refer to FIG. 3, deposing a gate isolation layer 3 on thegate 2 and the substrate 1.

The gate isolation layer 3 covers the entire gate 2 and substrate 1.

step 3, please refer to FIG. 4, deposing and implementingphotolithography process and etching process to pattern an oxidesemiconductor layer on the gate isolation layer 3 to form an islandshaped oxide semiconductor layer 4 directly over the gate 2.

Specifically, the island shaped oxide semiconductor layer 4 is an Indiumgallium zinc oxide (IGZO) semiconductor layer.

step 4, please refer to FIG. 5, sequentially deposing an etching stopperlayer, a photoresistor layer on the island shaped oxide semiconductorlayer 4 and the gate isolation layer 3, and then implementingphotolithography process to the photoresistor layer to form an islandshaped photoresistor layer 6 directly over the island shaped oxidesemiconductor layer 4, and etching the etching stopper layer to form anisland shaped etching stopper layer 5 on the island shaped oxidesemiconductor layer 4.

Furthermore, a width of the island shaped etching stopper layer 5 issmaller than a width of the oxide semiconductor layer 4; the islandshaped etching stopper layer 5 covers a central part 41 of the islandshaped oxide semiconductor layer 4 and exposes two side parts 43 of theisland shaped oxide semiconductor layer 4.

step 5, implementing ion implantation process to the two side parts 43of the island shaped oxide semiconductor layer 4.

Specifically, to the IGZO semiconductor layer, the ion implantationprocess is implemented with hydrogen plasma (H2 plasma). After thehydrogen plasma process, huge amount of H2 ions are implanted into thetwo side parts 43 of the island shaped oxide semiconductor layer 4 toreduce the energy gap of the two side parts 43 and raising theconducting ability thereof. Accordingly, the ohm contact resistancebetween the island shaped oxide semiconductor layer 4 and a source/adrain 7 formed in the following step 7.

Certainly, to the non IGZO semiconductor layer, specific ions can beselected and implanted according to the specific material of the oxidesemiconductor layer to realize the object of implantation to reduce theohm contact resistance between the island shaped oxide semiconductorlayer 4 and a source/a drain 7 formed in the following step 7.

step 6, please refer to FIG. 6, lifting off the island shapedphotoresistor layer 6 from the island shaped etching stopper layer 5.

step 7, please refer to FIG. 7, deposing and implementingphotolithography process and etching process to pattern a second metallayer on the island shaped etching stopper layer 5 and the gateisolation layer 3 to form the source/the drain 7.

The source/the drain 7 contact the two side parts 43 of the islandshaped oxide semiconductor layer 4 to establish electrical connections.Because the two side parts 43 of the island shaped oxide semiconductorlayer 4 are implemented with ion implantation process and the conductingability is enhanced. Therefore, the ohm contact resistance between theisland shaped oxide semiconductor layer 4 and the source/the drain 7 isreduced. Accordingly, the driving voltage and the power consumption ofthe flat panel display can be effectively diminished.

step 8, please refer to FIG. 8, deposing and implementingphotolithography process and etching process to pattern a protectinglayer 8 on the source/the drain 7 and the etching stopper layer 5 toform a via 81 located at one side of the island shaped oxidesemiconductor layer 4.

Specifically, the material of the protecting layer 8 is silicon dioxide(SiO₂) or silicon oxynitride (SiON).

step 9, please refer to FIG. 9, deposing and implementingphotolithography process and etching process to pattern a pixelelectrode layer 9 on the protecting layer 8.

Specifically, the material of the pixel electrode layer 9 is Indiumtitanium oxide (ITO) or Indium zinc oxide (IZO).

The pixel electrode layer fills the via 81 and contacts the source/thedrain 7 to establish electrical connections.

step 10, please refer to FIG. 10, implementing anneal process to thesubstrate 1 obtained in the step 9 to accomplish the manufacture of theoxide semiconductor TFT substrate.

Please refer to FIG. 9. On the basis of the aforesaid manufacture methodof the oxide semiconductor TFT substrate, the present invention furtherprovides an oxide semiconductor TFT substrate structure, comprising asubstrate 1, a gate 2 on the substrate 1, a gate isolation layer 3 onthe gate 2 and the substrate 1, an island shaped oxide semiconductorlayer 4 directly over the gate 2 on the gate isolation layer 3, anisland shaped etching stopper layer 6 on the island shaped oxidesemiconductor layer 4, a source/a drain 7 on the island shaped etchingstopper layer 6 and the gate isolation layer 3, a protecting layer 8 onthe source/the drain 7 and the etching stopper layer 6 and a pixelelectrode layer 9 on the protecting layer 8.

The island shaped oxide semiconductor layer 4 comprises a central part41 and two side parts 43, and the two side parts are implemented withion implantation process to enhance the conducting ability thereof; awidth of the island shaped etching stopper layer 6 is smaller than awidth of the island shaped oxide semiconductor layer 4 and only acentral part 41 is covered; the source/the drain 7 contact the two sideparts 43 to establish electrical connections. The ohm contact resistancetherebetween is smaller to diminish the driving voltage and the powerconsumption of the flat panel display.

The protecting layer 8 comprises a pixel electrode via 81 located at oneside of the island shaped oxide semiconductor layer 4, and the pixelelectrode layer 9 fills the via 81 and contacts the source/the drain 7to establish electrical connections.

Specifically, the substrate 1 is a glass substrate, and the islandshaped oxide semiconductor layer 4 is an IGZO semiconductor layer, andmaterial of the pixel electrode layer 9 is ITO or IZO and material ofthe protecting layer 8 is SiO₂ or SiON.

In conclusion, according to the manufacture method of the oxidesemiconductor TFT structure of the present invention, by implementingion implantation process to the two side parts of the island shapedoxide semiconductor layer, the conducting ability of the two side partsare raised and the two side parts contact the source/the drain, whichare capable of promoting the ohm contact between the oxide semiconductorlayer and the source/the drain to reduce the ohm contact resistancetherebetween. The driving voltage of the flat panel display can bereduced and accordingly the power consumption of the flat panel displaycan be effectively diminished; according to the oxide semiconductor TFTstructure of the present invention, by implementing ion implantationprocess to the two side parts of the island shaped oxide semiconductorlayer and contacts with the source/the drain, the ohm contact resistancebetween the oxide semiconductor layer and the source/the drain issmaller to reduce the driving voltage of the flat panel display and todiminish the power consumption of the flat panel display.

Above are only specific embodiments of the present invention, the scopeof the present invention is not limited to this, and to any persons whoare skilled in the art, change or replacement which is easily derivedshould be covered by the protected scope of the invention. Thus, theprotected scope of the invention should go by the subject claims.

What is claimed is:
 1. A manufacture method of an oxide semiconductorTFT substrate, comprising steps of: step 1, providing a substrate, anddeposing and patterning a first metal layer on the substrate to form agate; step 2, deposing a gate isolation layer on the gate and thesubstrate; step 3, deposing and patterning an oxide semiconductor layeron the gate isolation layer to form an island shaped oxide semiconductorlayer directly over the gate; step 4, sequentially deposing an etchingstopper layer, a photoresistor layer on the island shaped oxidesemiconductor layer and the gate isolation layer, and then implementingphotolithography process to the photoresistor layer to form an islandshaped photoresistor layer directly over the island shaped oxidesemiconductor layer, and etching the etching stopper layer to form anisland shaped etching stopper layer on the island shaped oxidesemiconductor layer; a width of the island shaped etching stopper layeris smaller than a width of the oxide semiconductor layer; the islandshaped etching stopper layer covers a central part of the island shapedoxide semiconductor layer and exposes two side parts of the islandshaped oxide semiconductor layer; step 5, implementing ion implantationprocess to the two side parts of the island shaped oxide semiconductorlayer; step 6, lifting off the island shaped photoresistor layer fromthe island shaped etching stopper layer; step 7, deposing and patterninga second metal layer on the island shaped etching stopper layer and thegate isolation layer to form a source/a drain; the source/the draincontact the two side parts of the island shaped oxide semiconductorlayer to establish electrical connections; step 8, deposing andpatterning a protecting layer on the source/the drain and the etchingstopper layer to form a via located at one side of the island shapedoxide semiconductor layer; step 9, deposing and patterning a pixelelectrode layer on the protecting layer; the pixel electrode layer fillsthe via and contacts the source/the drain to establish electricalconnections; step 10, implementing anneal process to the substrateobtained in the ninth step.
 2. The manufacture method of the oxidesemiconductor TFT substrate according to claim 1, wherein operations ofthe patterning are accomplished by photolithography process and etchingprocess.
 3. The manufacture method of the oxide semiconductor TFTsubstrate according to claim 1, wherein the island shaped oxidesemiconductor layer is an IGZO semiconductor layer.
 4. The manufacturemethod of the oxide semiconductor TFT substrate according to claim 3,wherein the ion implantation process is implemented with hydrogenplasma.
 5. The manufacture method of the oxide semiconductor TFTsubstrate according to claim 1, wherein material of the pixel electrodelayer is ITO or IZO.
 6. The manufacture method of the oxidesemiconductor TFT substrate according to claim 1, wherein material ofthe protecting layer is SiO₂ or SiON.
 7. The manufacture method of theoxide semiconductor TFT substrate according to claim 1, wherein thesubstrate is a glass substrate.
 8. An oxide semiconductor TFT substratestructure, comprising a substrate, a gate on the substrate, a gateisolation layer on the gate and the substrate, an island shaped oxidesemiconductor layer directly over the gate on the gate isolation layer,an island shaped etching stopper layer on the island shaped oxidesemiconductor layer, a source/a drain on the island shaped etchingstopper layer and the gate isolation layer, a protecting layer on thesource/the drain and the etching stopper layer and a pixel electrodelayer on the protecting layer; the island shaped oxide semiconductorlayer comprises a central part and two side parts, and the two sideparts are implemented with ion implantation process; a width of theisland shaped etching stopper layer is smaller than a width of the oxidesemiconductor layer and only a central part is covered; the source/thedrain contact the two side parts to establish electrical connections;the protecting layer comprises a via located at one side of the islandshaped oxide semiconductor layer, and the pixel electrode layer fillsthe via and contacts the source/the drain to establish electricalconnections.
 9. The oxide semiconductor TFT substrate structureaccording to claim 8, wherein the island shaped oxide semiconductorlayer is an IGZO semiconductor layer, and material of the protectinglayer is SiO₂ or SiON and material of the pixel electrode layer is ITOor IZO.
 10. The oxide semiconductor TFT substrate structure according toclaim 8, wherein the substrate is a glass substrate.
 11. An oxidesemiconductor TFT substrate structure, comprising a substrate, a gate onthe substrate, a gate isolation layer on the gate and the substrate, anisland shaped oxide semiconductor layer directly over the gate on thegate isolation layer, an island shaped etching stopper layer on theisland shaped oxide semiconductor layer, a source/a drain on the islandshaped etching stopper layer and the gate isolation layer, a protectinglayer on the source/the drain and the etching stopper layer and a pixelelectrode layer on the protecting layer; the island shaped oxidesemiconductor layer comprises a central part and two side parts, and thetwo side parts are implemented with ion implantation process; a width ofthe island shaped etching stopper layer is smaller than a width of theoxide semiconductor layer and only a central part is covered; thesource/the drain contact the two side parts to establish electricalconnections; the protecting layer comprises a via located at one side ofthe island shaped oxide semiconductor layer, and the pixel electrodelayer fills the via and contacts the source/the drain to establishelectrical connections; wherein the island shaped oxide semiconductorlayer is an IGZO semiconductor layer, and material of the protectinglayer is SiO₂ or SiON and material of the pixel electrode layer is ITOor IZO; wherein the substrate is a glass substrate.